14.02.2022: Ocean Circulation and Climate Dynamics Colloquium

Dr. Antonietta Capotondi, University of Colorado/CIRES and NOAA/PSL: "Tropical Pacific Decadal Variability: How well do we know it?"

When?     Monday, 14. February 2022 at 4 pm
Where?    ZOOM meeting room: https://geomar-de.zoom.us/j/89824859405?pwd=aTNXVzVTTnVlUzh6Z1FvUHRlZUVtdz09

Meeting-ID: 898 2485 9405
Kenncode: 231229

The Pacific Ocean exhibits pronounced decadal variations, which have been described in terms of the Pacific Decadal Oscillation (PDO) over the North Pacific, and the Interdecadal Pacific Oscillation (IPO) over the entire basin. These modes of variability have a strong tropical component, which may drive decadal phase transitions, according to recent studies, and is associated with important worldwide impacts. The tropical Pacific also hosts the El Niño Southern Oscillation, the dominant mode of variability at interannual timescales, so that a plausible “null hypothesis” is that tropical Pacific decadal variability (TPDV) is merely a residual of interannual ENSO variations. However, several “slow” oceanic processes could contribute to variability at decadal timescales, including changes in the strength of the upper-ocean overturning circulation, known as Subtropical-Tropical Cells, adjustment processes via propagation of extratropical oceanic Rossby waves, and advection of temperature anomalies along the main pycnocline from the subtropical regions to the equator, but the influence of these processes on equatorial SST anomalies, as well as their relative importance, are still unclear. This talk will provide a synthesis of our state of knowledge of TPDV, revisit its main proposed oceanic mechanisms, and discuss their potential relevance.

 

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